Anybody can help me by giving an idea on how to make a 4 to 20mA variable current source. The current can be varied using a potentiometer. The output current should be ir-respective of the load resistance.

Anybody can help me by giving an idea on how to make a 4 to 20mA variable current source. The current can be varied using a potentiometer. The output current should be ir-respective of the load resistance.

Thanks in advance,
- Ganapati

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What power supply voltage do you intend to use to power this current source circuit? 5V, 12V, of something else?

Since the chip has got ref. voltage outputs you only need a pot to make an adjustable 4-20mA output. You say that you want any load resistance, that is depending on the supply voltage. You will need more voltage to generate 20mA in a 1k resistor than a 100 ohm resistor. With a max supply voltage (<40V) you can use loads of more than 1k5. This is way more than the normal measurement load resistors in the hundred of ohms range. Remember to use a high power transistor with a cooling fin, if you use a high supply voltage and 20mA for some time on a low load resistor.